


Hidden Attraction

by orphan_account



Category: Undertale (Video Game)
Genre: Bondage, Choking, Dom!Underfell!Sans, F/M, FaceFucking, Just basically BDSM, Orgasm Denial, Other, Petplay, Slight Underfell!Paps x reader, Sub!Underfell!Sans
Language: English
Status: In-Progress
Published: 2016-06-03
Updated: 2016-06-09
Packaged: 2018-07-12 01:42:19
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 11
Words: 8,978
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7079422
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: <blockquote class="userstuff">
              <p>They always said that monsters lived underground to scare children away from Mount Ebbot... or did they? You fell down a cliff in Mount Ebbot while looking for your cousin, who was nowhere to be found. You did not expect any of this to happen, not at all.</p>
            </blockquote>





	1. Fallen Down

**Author's Note:**

> Welp, this is my first fanfiction on here! I hope you enjoy!

"___, sweetie!" Your aunt called. You have been staying there for the evening since your parents had to go to a meeting. 

 "Yes?" You called back.

 "I can't find your cousin!" She said distressingly. "I've looked everywhere; the whole house, the backyard, the shed... I can't find him anywhere!"

 "Where do you think they could be?" You asked.

 "I don't know," She replied. "All that I do know is that they disappeared an hour ago after I told them the tales of the monsters!"

 "I'm going to Mount Ebott," You decided.

 "But ___, dear, it's dangerous!" She protested. "It's a long walk, your feet will hurt too!"

 "I'll do it for them," You said. "I'm worried sick and I'm not losing my baby cousin because I was too lazy and scared to go to Mount Ebott!"

 "Fine, but please dear... be safe," Your aunt pleaded. "Here's your cellphone. You know my number."

 You grabbed your phone and headed out the doors. You did not know where Mount Ebott was, however. You've heard it was north by some, and that it was west by others. You didn't want to get lost, so you decided to look it up. You searched it up, which took a long time since your parents didn't think you needed much data, but it worked. You headed the direction that it told you to go, and ended up in front of a large mountain; this was the fabled mountain of the monsters.

 You put your phone in your pocket and started to climb the mountain. It was steep but it had a lot of ledges that poked out. You grabbed onto them and put your foot on the lower ones cautiously. After twenty minutes of climbing, you were at the peak. It was flatter than you imagined, much like concrete. You called for your cousin, but to no avail. You kept looking for what seemed like forever and decided to give up. He must be at home playing a prank on you like he tended to do.

 You were heading back before your feet slipped and you suddenly felt weightless. You screamed as you fell down the fabled 'barrier' of monsters. You appeared in a bed of flowers, suddenly feeling very sleepy. You tried not to give in to your drowsiness, but you couldn't hold up much longer. You finally gave in and fell into unconsciousness.


	2. Burnt Pie

**Summary for the Chapter:**

> You meet a talking Flower and have some burnt pie with a motherly yet psychopathic goat. You escape her home, Flowey dying in the process, and land in a snowy forest.
> 
> Welcome to Snowdin!

**Notes for the Chapter:**

> I might post three chapters today to set ground for the story! (including the first one) So yee... enjoy! ^^

You woke up on the same golden bed of flowers you seen before blacking out. There was blood staining them, mixing delicately with the gold. It wasn't much, thankfully. Your head might've been scraped or something, nothing major. It did hurt though, your legs were weak too. And how long had you been passed out for?

You scrambled to get up as you walked weakly forward. Where were you going? You didn't know! Somewhere, anywhere! You might've stood up too fast though, because your head was pounding. You were stopped by a golden flower mid-path. It looked as if it was in rough shape with some rips and tears in its six leaves. Somehow, it could... talk? What's with this place?!

"Howdy, you look like you're hurt," It said. "I'm Flowey by the way."

"Hey Flowey," You managed to get out. "I'm fine, I just have a headache."

"Oh, you're new here, aren't you?" He muttered. "Let me take a look at your head, you must have fell."

You bent down so he could examine your head. It hurt your head more, but he might be able to help if you had any serious injuries.

"You look okay, it's just got a scrape on it. You did say your head hurts? I can help, follow me," He said, he disappeared into the ground and reappeared in front of you.

You followed him. It was rather awkward, though, since he couldn't walk. He stopped in front of a sign, trying to hide. He was sweating out of nervousness. 

"Here, take this gold," He said. "Try not to let them see you, just your hands. Ask for some pills for your headache, whatever they have."

You began to sweat with nervousness as well as you walked up to a stand. It was selling all kinds of things and was ran by a humanoid dog critter. He looked like he could kill you in an instant. Luckily, the stand was taller than you so you didn't have to crouch down to hide your face. You lifted your arm up all the way and laid some gold on the table.

"What's this for..." It questioned.

"C-Can I have something to h-help with headaches?" You asked.

"Sure," It replied, handing you a bottle and some water.

You walked back to Flowey, holding the bottle. You were scared of what might happen if a monster caught you. I mean, they were sealed under here for a reason? Weren't they...?

"Oh, good!" Flowey said nervously. "Take those and you'll feel better."

You opened the bottle of pills and took one out. It was white and shady-looking, but you'd do anything to get rid of this terrible headache. You popped it into your mouth and swallowed it along with some water. 

"Thanks for helping me, by the way..." You thanked him. "Why were the monsters sealed under here anyways?"

"Well, they were sealed here because they were bloodthirsty creatures. They wanted to kill humans and take their souls and the humans found out why their family members were disappearing and sealed us underground. It wasn't fair to some monsters though, but ninety-nine percent of them were evil..." He explained.

"O-Oh..." You were suddenly scared when you seen a goat woman appear. 

"Have you fallen? Are you okay?" She asked.

"Don't trust her..." Flowey whispered.

"I-I'm fine," You said, shivering in fear as you picked up a flower pot and put Flowey in it, carrying him with you.

"Follow me, I'll help you," She said, leading you to a tidy house.

You were lead into a kitchen, you smelt some pie, but it was burnt. She must make an effort at least..?

"Would you like some pie?" She asked. "It's very delicious, if I say so myself."

"Um... sure..?" You said reluctantly. 

"Oh, I forgot to tell you! My name is Toriel! And you are..?" 

"I'm ___," You replied.

She cut open the pie and gave you a slice. You tried not to gag at the smell of it. You did need something to eat, though. That fall took most of your energy and this could possibly help. You ate all the pie, trying not to puke. At least Toriel was pleased that you liked it.

"Well, now it's late isn't it?" Toriel said. "Go on to bed, you're room is the first room on the left in the hallway."

You walked in the direction she told you to go. You walked into a room that was pretty clean. It had a small bed, a nightstand covered in dust, and a clock. How did they know the time if they lived underground? Heck if I know. It was only six PM, what the heck, Toriel? 

"We need to escape," Flowey whispered.

"I can try..." You said. "How?"

"She goes to sleep by now, there's an exit to the rest of the underground downstairs," He explained. "We need to go now!"

You walked downstairs into a purple room. It was plain with no decoration besides a door at the end of a long hallway, you ran towards it. You were about to open it, but were stopped by a flaming fireball being thrown your way.

"Watch out!" Flowey said as he took the blow for you.

"Flowey!" You cried. He was gone, his flowerpot dust now.

"You brat!" Toriel yelled. "I take you in and feed you and this is the thanks I get?"

You pushed open the door and ran out before she could take a hit on you. Luckily for you, the door was unlocked. You fell on your knees from running out too quickly and scrambled to get up. You were in a snowy forest, it was beautiful. You padded forward, landing near a sign. 

"Welcome to Snowdin!"


	3. Sans The Skeleton

**Summary for the Chapter:**

> You meet a skeleton named Sans who is strange to say the least...

You were freezing your ass off in the cold here. Under normal circumstances, you'd run to the nearest hotel or store to get warm, but these monsters were venomous and would kill you before they thought about it. You let out a frustrated sigh and continued. If only you'd of worn a long sleeve shirt instead of a tank top and shorts. But it was freaking hot up there! 

You followed a path that might've previously had snow shoveled out of the way, but was now covering ninety percent of it again, your feet crunching in the snow. You stopped in front of a bridge, there was a skeleton in front of it! He wore a big black jacket with white fur on the hood, a red sweater, and some basketball shorts. He had fangs, one of them golden, and one of his eyes were glowing red. Needless to say, you were scared shitless.

"heh..." He smirked. "a human. that's hilarious."

"P-Please don't kill me..." You stuttered, shaking because your fear and how cold it is.

"i won't, i have no use to," He said. "if i wanted to, i would have when i first saw you, which was five minutes ago..."

"W-Who are you?" You asked.

"heh, the name's sans. sans the skeleton," He said.

"I-I'm _-___..." You said, rubbing your arms to warm them up.

"here, you look cold," He said, handing you his jacket as you blushed. "hey, don't think i care about you or anything. i just don't want a human popsicle."

You walked for a while, silently. Your feet were numb from wearing flip flops, but his slippers weren't better than that at all. It was freezing out here, colder than your hometown ever got, even in the coldest nights of winter. Why was it so cold if it was underground anyways, it can't snow under here! You wondered what area of your city you were under right now, were you even still in your city? You didn't have much time to ponder that because you've reached a house deep in the town of Snowdin. Sans scrambled to get some keys out of his jacket's pocket.

"let's go on in and i'll warm ya up...~" He said. He didn't mean... wait... what?!

 

**Notes for the Chapter:**

> I thought ending it here would be appropriate for warning of NSFW purposes. But like anyone cares about that, lol right? But yea... see you in the next chapter which won't be short af like this one!


	4. New Pet (NSFW)

**Summary for the Chapter:**

> Sans decides to test out his new pet.

**Notes for the Chapter:**

> Just gonna warn ya, there's NSFW in this chapter.
> 
>  
> 
> You have been warned.

He twisted the keys and opened the door, putting the keys back in the jacket you're wearing. The room you stepped in was dim, even with the lights on. Your eyes quickly adjusted to the darkness as you observed the room. It was the living room and you gasped when you saw a taller, more frightening skeleton on the couch. He was wearing huge gloves, black and red clothes, and he looked far more evil than Sans.

"BROTHER..." He said. 

"y-yes boss..." Sans said. He seemed... fearful? Why? And why did he call him 'boss?'

"WHY THE FUCK DID YOU BRING A FILTHY HUMAN INTO OUR HOME!?" Now you knew why.

"w-well... i thought we could t-turn her in after k-keeping her for a while..." He said fearfully.

"VERY WELL THEN..." He said. "HUMAN. I AM PAPYRUS. YOU WILL MAKE YOURSELF USEFUL OR YOU WILL GET OUT."

You gulped. You noticed he was waiting for a reply. "Y-Yes sir.."

"HEHE... WHAT A PATHETIC EXCUSE!" He chuckled. "I COULD KILL YOU IN AN INSTANT! HUMANS ARE SUCH A WEAK FORCE OF LIFE!"

You felt offended, but too scared to protest.

"GO MAKE YOURSELF USEFUL SOMEWHERE ELSE, I DO NOT WANT TO SEE THE LIKES OF YOU," He commanded.

Sans lead you upstairs and into a really messy room. 

"heh, i guess it's time to try out my new pet~" He smirked. "on your knees."

You were about to obey, not because you wanted to, you were just scared of what would happen if you didn't, but apparently you didn't respond quick enough. He pushed your shoulders down. It hurt, and it looked like he was barely pushing you down. Maybe he didn't know his own strength... 

You wondered what would happen next as he opened his messy closet, pulling out... a collar? There was a flash of red light, and he was gone. You gasped, feeling the collar being wrapped around your neck. You turned around, seeing no other than Sans. How the heck did he get there? He wrapped it tightly so you were close to choking, but not choking at the same time.

"heh... it suits you," He said with a large smirk on his features, his shorts now dropped to the floor.This was highly degrading. "open wide~"

You kept your mouth closed, embarrassed and angry. Why would he put a collar on you? You weren't a dog! You weren't his pet! You were snapped out of your thoughts when he yanked the chain, choking you. You gasped for air and he stopped, stuffing your mouth full with his red member.

"suck," He demanded. You refused. You would bite down on it, but it was too big for you to close your jaw. "fine t-then, we can do this my way. i-i was trying to go easy on ya..."

He winked before he started to thrust in your mouth. You could barely breath like this. Wearing this tight, degrading collar was enough, but having someone facefuck you while you were wearing it? How could anyone handle that?

"look. at. me." He said, hooking his thumb under your chin and forcing you to, whether you liked it or not. "mmm..."

He continued to thrust, you making choking noises every few thrusts. He removed his thumb as you continued looking at him, tears falling from your eyes. Now he was thrusting all the way down your throat, choking you. 

"f-fuck... i-i'm about to..." He panted in between thrusts.

He suddenly grabbed the back of your head, tangling his hand in your hair as his thrusts became erratic. After a few more, he came, filling your mouth up with red fluid. He waited a minute before pulling out.

"Swallow." He demanded. You nodded fearfully and swallowed, trying not to gag.

After swallowing, you coughed and gasped for air. He chuckled at you as he put his shorts back on. You finally caught your breath after a few minutes of deep breathing. 

"oh would you look at the time..." he muttered. "it's nine o' clock, time for bed, sweetcheeks."

"W-Where do I sleep..?" You asked exhaustedly. 

"where d'ya think?" Sans said, smirking as he pointed at his bed.

"I-I have to sleep in y-your bed with you?" You asked. You felt like a child.

"don't want ya runnin' off..." He said, shrugging.

"Fine," You said as you laid on the bed next to him. 

He was cuddling with you like you were his life-sized teddy bear, suddenly being gentle with you. He stroked your hair as you felt yourself getting sleepier. You ended up falling asleep in his arms, which were more comfortable than they sound.


	5. Mornings With Papyrus (NSFW)

**Summary for the Chapter:**

> Morning with the skeleton brothers gets a bit hot after Sans leaves for work...

**Notes for the Chapter:**

> This took forever to make because my wifi was acting up, please forgive meh. Have a digital cookie! ^^ 
> 
> \----> ( : : )
> 
>  
> 
> (I'm so childish)

You woke up in Sans’s bed, your jaw strained from the night before. He was still sound asleep, holding you protectively in his arms. You struggled to get up, but he was holding you too tight. For a sack of bones, he was pretty heavy. How much did he even weigh? You were snapped out of your thoughts when he finally got up. He looked shock for a moment before his expression changed back to normal.

“heh, forgot you were there, kiddo,” he mumbled before he let go of you.

He stood up, yanking you up too by the chain of your collar. You choked as you were dragged into the kitchen of the home. It too was dim like the rest of the home. He sat down at the table, putting you in a seat next to him. At least you didn't have to sit in his lap. Your stomach started growling when you smelt the boiling pasta on the stovetop. The person cooking it was none other than Papyrus.

"HUMAN, MY BROTHER HAS TOLD ME YOU HAVE BEEN VERY USEFUL LAST NIGHT," Papyrus said with a smirk as he stirred the pasta. Was he  _trying_ to make you embarrassed!?

"I-I was I guess..." You murmured. You figured this guy was always wanting a reply.

"don't just guess you were, you're an amazing pet," Sans said, smirking as your face flushed red.

"OH, YOU'VE USED THAT COLLAR? CAPTURING A HUMAN IS THE ONLY THING YOU'VE NEVER FUCKED UP IN YOUR LIFE, SANS," Papyrus said, Sans slightly wilting at his words.

"yea, and i'm surprised i'm the one who did it. am i still the lazybones here?" Sans said.

Papyrus froze in place before turning around. "SANS. DON'T PUSH THE LIMITS YOU BONEHEAD. I WORK TWICE, IF NOT THRICE, AS HARD AS YOU!"

"then why'd i catch the huma---" Sans was cut off with a slap to the face.

"NYEHEH, DON'T GET TOO COCKY, BROTHER," Papyrus said, evilly laughing.

Sans rubbed his cheek as you tried to hold in your laughs. Sans noticed this and yanked the chain again, choking you. When he released it you took deep breaths of air as you were served a small plate of spaghetti. It didn't look that appetizing, but you were hungry. You twirled a fork in it and tried it, Papyrus staring you down. It tasted like shit and you really wanted to gag, but you swallowed it anyways, fearing what he would do if you didn't.

"WHAT DO YOU THINK? I AM GREAT AT COOKING, AREN'T I? ESPECIALLY AT SPAGHETTI, THAT'S WHY I MAKE IT EVERY DAY!" Papyrus said. This was a rare moment he wasn't completely evil.

"I-It's great l-like you!" You said.

You managed to choke down the rest of the disgusting spaghetti. How did Sans eat this every day, I mean it's gotta drive you mad if you eat trash every day. He must want to keep his brother happy. Who wouldn't want to anyways if he's already that much of an asshole when he's happy. 

"welp, i'm off to work, see ya at twelve," Sans said. "boss, take care of the human while i'm gone and don't let them run off."

What surprised you was that Sans was gone after snapping his fingers. How? He didn't open a door or anything. Papyrus noticed your astonished look and decided to explain.

"SANS CAN TELEPORT USING MAGIC, HE CAN ALSO MOVE THINGS, MAKE HIMSELF THINGS, JUST GENERAL MAGIC..." Papyrus said briefly.

"Do y-you have magic?" You asked.

"NOW WOULD YOU LIKE TO FIND THAT OUT YOURSELF?" Papyrus said. What was it about his voice... was it... lust?

"What do you m-mean by that?" You were flustered now.

"HOW ABOUT I SHOW YOU..." He picked you up and sat you on the counter, smirking when he did it.

You gasped when you felt your clothes being ripped off your body along with your bra . He stared at your breasts in awe when he seen them. You blushed as he examined them, feeling the urge to cover up. 

"NOT BAD FOR A HUMAN..." He said despite never even having seen a human before you.

He squeezed your breasts hard, eliciting a quiet moan from you. He looked pleased with himself as he kept on squeezing before trailing his hands downwards. You had your legs closed shut, his expression was unreadable right now.

"Open your legs, pet," He demanded in a dark voice. "And don't make a fucking sound."

You complied because of his threatening look. You gasped as he started to rub your clit under your panties. It was easy to hold in the moans, well it was until he picked up the pace. You felt a wet spot forming on your panties, were you enjoying this? You were left no time to think when he went even faster. You were so close, just a little bit more... He stopped rubbing and examined you as you let out a barely audible whimper at the loss of contact.

"You seem to be enjoying this, human..." Papyrus said with a smirk. "You're some kind of freak, aren't you?"

He left you no time to reply as he shoved a finger in you and started moving it, rubbing you with his thumb as well. You struggled to hold in the moans that were threatening to spill out as he added a second finger. He moved it in time with the others as you refrained from rolling your hips. He added a third and you couldn't hold back anymore. You let out a moan as you rolled your hips against his fingers. He pulled his fingers away again, putting them in his mouth.

"Tastes pretty good..." He said before diving between your legs.

You moaned as he flicked your clit lightly with his tongue. He continued licking downwards, teasing your entrance with his tongue. You moaned louder when he pushed it in, tasting you even more. You were close as you rolled your hips against his face. Much to your disappointment, he pulled away again.

"Someone seems eager to get to the real fun..." Papyrus said, looking down at the panting mess you've became as he pulled down his pants. "Beg for it..."

You were too caught up in your lust to think about it when you shyly spoke. "P-Please, Papyrus, f-fuck me..." 

"I know you can do better..." He said, teasing your entrance with his member.

"P-Please fuck me with your cock!" You begged.

You let out a deep moan when he finally slid in with a pleased sigh. It hurt, but it was too good to stop. He didn't wait for you to adjust as he started rocking his hips at a fast pace. You felt beads of sweat glistening on your forehead as you were pounded into the wall. You moved your hips in time with his thrusts as you felt yourself reach your peak. White clouded your vision as you tightened around his member, triggering his as well. He thrusts became more erratic as he filled you up. He waited a minute before pulling out. 

He stepped away to observe what he did with an evil smirk, cum dripping out of your womanhood. "Absolutely disgusting."

You panted as you came down from your high.

"Go take a shower, I don't want our human reeking of sex."


	6. Showertime (NSFW towards the end)

**Summary for the Chapter:**

> After a shower, you're clean for the first time in days. Sans decides to have a little fun with you afterwards.

**Notes for the Chapter:**

> Sorry if there's too much NSFW for your liking... 
> 
>  
> 
> *hides* 
> 
> I just like NSFW lol

You walked into the bone brothers' bathroom and cut on the light. It was kind of spacey in there, so you had plenty of room so you didn't feel smothered. You walked over to the shower, moving the see-through curtain to the side, and cut the water onto a comfortable temperature. While it was warming up, you were going to get yourself a towel. You walked into the living room to ask Papyrus where they were.

"Papyrus, where are the towels?" You asked.

"THEY'RE IN THE CLOSET TO THE RIGHT OF THE HALLWAY," He told you before averting his gaze when Sans appeared.  

"hey boss," He greeted casually before his eyes landed on you. "what happened here?"

"um...." You were about to speak but you were cut off by Papyrus.

"THAT IS NONE OF YOUR BUSINESS BROTHER, SHE WAS JUST ABOUT TO TAKE A SHOWER. NOW GO WATCH HER AND MAKE SURE SHE DOESN'T RUN AWAY," He said, pointing to the bathroom.

Sans grabbed your hand and roughly pulled you to the bathroom. He pinned you against the wall as you felt fear emerge. He looked at you like a predator as he ran his hand through your hair. 

"i could just fuck you right now, kid," He said, running a hand from your cheek and down your body. 

His hand reached your inner thigh. You felt a warmth grow in your womanhood as he started to rub. Moans slipped from your mouth as he massaged your breast with his other hand. He kept on doing this for a few minutes, leaving the water running. You felt yourself get close, only to have it ruined when you two were interrupted.

"SANS! NO PLAYING WITH THE HUMAN RIGHT NOW!" Papyrus yelled as he walked by the room.

"here's a towel since i have to sit here and watch you," He said with a shrug as he handed you a towel and sat down in a chair.

You put the towel on a rack and stepped into the shower. You found some soap lying in the bottom of the tub and picked it up, giving Sans a full view of your ass. He licked his lips unconsciously as you stood back up. You rubbed the soap along your body, being sure to clean yourself thoroughly after being fucked by Papyrus. Your gaze fixed on Sans for a moment, who had a hand down his shorts as you showered. Damn these see through curtains!

"Um... Sans," You said angrily, snapping him out of it as he pulled his hand out. "How am I supposed to wash my hair?"

"i bought some shampoo and conditioner on the way home for ya since you'll be here for a while" He said, smirking visibly as he handed you a bag.

You took out the contents, getting water in the bag, and set them in the shower. You squeezed some shampoo in your hand, running it through your hair. After you were done washing your hair, you cut off the water and grabbed the towel, drying yourself off before wrapping it around your body and stepping out of the shower. 

Sans roughly grabbed your wrist again and pulled you into his bedroom. You blushed as you were pinned underneath him on his bed, sweating nervously. You hadn't even had the chance to take off your towel. You glared at him, but the look was soon lost when he threw the towel off of you..

He was soon trailing his hands all over your body. He smirked as he grabbed your breasts, his ears eating up the moan that came from you when he did. His hands continued downwards as he felt his magic surge within him. His face was red, which you still didn't know what it meant, as he suddenly pushed a finger inside you. You moaned and rolled your hips against it.

"wow, someone's eager..." He said as he pulled down his shorts.

He suddenly, without warning, pushed inside your entrance. You moaned as he gave you a minute to accommodate to his large size. He was much more gentle with this than his brother. You gave an approving nod when you were ready.

He started to thrust slowly, moaning every few thrusts. You were trying not to roll your hips as he picked up the pace. You moaned as he suddenly started going faster, making the bed creak. You gripped the bedsheets as you felt yourself getting close. Your walls tightened around him as you moaned incoherently. He came soon after, filling you up before pulling out. You laid there for a minute, panting while he put his shorts back on.

Luckily for you, he had a towel in handy. He cleaned you up with it before handing you some of his clothes. You slipped on a huge red sweater of his, some sweatpants, and put your hair in a ponytail, which he seemed to find sexy because he was drooling. You blushed at this, he noticed and wiped away the drool, his cheekbones reddish. What did that even mean?

"What does it mean when a skeleton's cheekbones are red?" You asked.

"that's not important. we're leaving to go to the store in a couple of minutes, by the way," He said. You were going to have to ask Papyrus next time you're alone with him. 


	7. Shopping (More NSFW...)

**Summary for the Chapter:**

> You and the skeleton brothers do some shopping.

**Notes for the Chapter:**

> I told you there will be bondage, there shall be bondage.

You headed out the door with Sans and Papyrus to go to do some shopping. Sans didn't tell you anything about where you were going, so you were kind of excited. You walked to the local store first, to buy some groceries and clothes. The store looked like it had much more stuff than on the surface. Papyrus and Sans split paths, you going with Papyrus while Sans did some shopping for himself.

He lead you to the spaghetti aisle, of course. He already had like twenty boxes of that stuff, why did he need more? You pushed that thought aside as he grabbed twenty more boxes and walked to the next aisle. He grabbed five cans of sauce before he finally got out of the pasta aisles. You two walked to the clothing aisle, which had a lot of lady clothing in it. He grabbed a lot of outfits for you, which you picked out a few, but he picked out most. They were all black, red, and yellow themed.

Sans was back shortly to join you two, carrying three large bags in hand. You left the supermarket and went to get something to eat at Muffet's Teahouse, which recently opened due to the successful fundraisers Muffet had ran. She was a bit greedy with her money, but she made amazing pastries. Sans ordered some Spider Cider and a donut, Papyrus ordered spaghetti and got angry when they didn't have any, and you ordered a brownie dish and some tea. (because who doesn't love brownies?)

"I CAN'T BELIEVE THIS RESTAURANT!" Papyrus said angrily, slamming his hands on the table angrily.

"We can't serve you spaghetti, but you could always play with my pet... for free. Ahuhuhu~" Muffet chimed before heading off to fix your food.

"Sans, those bags are huge," You commented. "What's in them?"

"oh we'll get to that later~" Sans said in a husky tone. Now you were really intrigued about those bags.

"Here's your plates dearies! Ahuhuhu~" Muffet said, handing you all your food.

Sans took a look at the clothes you bought for yourself.

"hehe, nice clothes, can't wait to rip them off," He growled into your ear as your face flushed.

Sans ate his donut in a record of thirty seconds while Papyrus sat there pouting about spaghetti. For such a tough guy, he acts like a child sometimes. You ate the brownie dish in a few minutes, which was surprisingly delicious to be made for spiders. The tea had... spider blood in it..? You threw it out while Sans sipped on his Spider Cider on the way out.

When you got back to the house, Sans and Papyrus sat in the living room with you, watching MTT's  _Would You Smooch A Ghost?_  

"heh, you're lucky we're letting our pet on the furniture today," Sans said, holding your chain in hand as you gave him a dirty look.

After watching the thirty minute long television program, Sans took you back to his room. Were you ever going to be away from them? Probably not. 

"so you want to know what's in the bag?" He asked as you nodded. "fine, i guess i'll _let the cat out of the bag_."

Sans dumped the bag onto the bed in between you two, gasping at what you saw. It was an assortment of sex toys and bondage items. Was he going to use these on you today? You hoped not but a part of you said yes, were you actually growing to like this? What were these skeletons doing to you!?

Sans took off your shirt along with your bra, pants, and panties. You were stripped now as he tied your hands to the headboard of his bed. Your face flushed a million shades of red as you realized that you looked oh so vulnerable and helpless. Sans chuckled at your reaction as he pulled out a dildo from the bag. He was going to have some fun with his pet before the real action began.

Without warning, he jammed it into your womanhood as you winced at the sharp entrance. You moaned as he started to move it in a fast motion. You started to buck your hips against it before instantly regretting it. He took it out as you gave a soft whimper due to loss of contact.

"now we can't have that, can we? who said the pet was in control~" He said.

You were confused for a moment before realizing what was happening. He tied your feet to the other side of the bed as well, preventing any movements below your hips. Your body was in it's most vulnerable state it could be in at the moment as he jammed it back in, going even faster. You moaned and writhed as you felt yourself getting close.

You felt your walls tighten as you let out a loud moan, coming for the first time today. He withdrew the toy and put it in a drawer beside the wall before he walked back over to your satisfied form. You gasped as you felt him lick your womanhood, which was becoming overstimulated. He flicked your clit with his tongue before plunging into your entrance with it. You felt yourself nearing orgasm again, but before you could reach it he stopped, leaving you a panting mess. He left your sight, only to be back again in front of you.

"tastes pretty good... want a taste?" He said as he pressed his teeth to your lips.

He asked for entrance, when you denied, he yanked your chain. You parted your lips as the appendage slid in, exploring your mouth. You moaned into the kiss as it deepened. A string of saliva connected you when you parted the kiss. You gasped as you felt his member tease your entrance.

It teased for a few minutes, stimulating you even more before finally sliding in with a pleased moan. He bucked his hips mercilessly into your womanhood, harder than ever before. Playing this out must've really gotten him going, it seemed. He made the bed creak with every movement of his hips, drawing out incoherent mewls from you along with them.

You felt yourself reaching your peak again, and you could tell he was too. You moaned loudly as you had the most intense orgasm you've felt before. Sans came inside you and pulled out, the fluid leaking from in between your legs. He smiled as he observed his handiwork before untying you. 

You felt happy to move your arms and legs again as you grabbed a towel and cleaned yourself off. Sans smirked smugly as he walked near you. You were on your knees on the bed, him towering over you at this angle.

"hey, since you've just cleaned yourself off, mind cleaning me off?" He said smugly as he positioned his member in front of your face.

You obliged to his orders because of what happened every time you didn't. You took in the head of his member, receiving a pleased sigh from him when you did. You licked from the bottom to the tip. After a few minutes, he was cleaned off and it was nine PM. You drifted off to sleep in his arms as usual again.


	8. Showtime (NSFW...)

**Summary for the Chapter:**

> You go to an MTT show with Sans and Papyrus, but that takes a whole different turn.

**Notes for the Chapter:**

> I really need to stop with the smut, lol. But Sans needs his sex so don't blame me! c;  
> *points at Sans*
> 
>  
> 
> Sorry if this chapter is kind of short but we're gonna have some major character development in the next chapter.

You woke up beside Sans, who was already awake. He seen you were awake and you went to get dressed. While you were dressing, he told you some good news. 

"hey kid, we're going to see a play today," Sans said, holding three tickets to Mettaton's show today. 

"T-That sounds fun," You said.

"but if you're going with us, i need you to do something for me," He said with an evil smirk. What was he planning now? "here, put these on."

He handed you a pair of black lacy panties. They seemed ordinary enough, except you felt a small lump in the fabric where your clit was. You didn't question it and put them on. Sans chuckled at this for some reason as you headed out the door where Papyrus was waiting. Sans teleported you to the gate of the show and handed them the tickets.

You walked into a crowded stage and took a seat at the front. You waited for a bit before a square shaped thing---looking like an overgrown calculator--- wheeled onto the stage. He started to sing, which wasn't really singing since he sounded too robotic, and almost all of the monsters began cheering obnoxiously. You were sitting in between Sans and Papyrus, in front of a group of teen boys.

At the end of the song, everyone cheered, including you just so you weren't rude. After that, it was extremely quiet besides low whispers. You suddenly felt something vibrate against your clit. You screamed internally as you glared at Sans, biting your lip to contain a moan. He looked at you with a smirk.

"is something wrong, you look like you've just seen a murderer" Sans said, acting like he didn't know what was going on.

You spotted a control in his hand, which he just turned up. It started vibrating harder. You bit your lip hard enough to draw blood but couldn't help the soft whine that came out of your mouth. A boy from the seat above you glared at you before continuing in his business. Sans turned it up even more, you shivering from the pleasure. You moaned softly and luckily, nobody paid any mind to you as Mettaton came back onstage for another song. 

You felt yourself close as your legs shook. You felt yourself tighten as you grabbed Sans' jacket, muffling a moan in it as you came. Sans was smirking at you. You panted as you attempted to recollect yourself, but you were left no time to because he put the dial on an even more intense setting. Your legs shook even harder as you came a second time. 

After a few songs sang by the robot, you were on your seventh orgasm so far. You were tired and whimpering from overstimulation. Finally, he showed you mercy and cut it off. After the show was over, you couldn't walk because your legs were so weak from all of the stimulation. Sans picked you up and carried you back to the house.

He laid you on the bed as you covered up. It was only five PM but you were really tired so you bundled up and drifted off to sleep.


	9. Emerging Feelings

**Summary for the Chapter:**

> Reader-Chan is starting to feel strange feelings for Sans and accepts the fact that they like the way they're treated sometimes. Sans is trying to push away his feelings as well, but how long can they keep this up?

**Notes for the Chapter:**

> *Undertaleismylife tells you to be honest with your feelings.
> 
> *. . .
> 
> *It has no effect.

(Sorry for the very slight change with the POV, it'll change back in one paragraph) 

Sans sighed as he woke up beside you. He loved how peaceful you looked in your sleep. Sans had began to develop.. strange feelings for you lately. No monsters were supposed to feel this way, monsters here were ruthless and uncaring. But Sans was different. Sans tried to hide it, of course. But he knew he couldn't hide forever. There'd be a day someone would see through everything. He groaned as he tossed that thought away and woke you from your sleep.

[See? POV is back now :3]

You woke up by Sans shaking you. You groaned before getting up after a minute. Sans looked.. different today. You couldn't put your finger on it but he did look weird. You got dressed in new clothes for today, some black jeans with a red sweater, and put the ones you wore yesterday in the clothes hamper. You did have to admit, Sans and Papyrus weren't that bad. You didn't like Papyrus and you didn't hate him. When you come to think about it, you think Sans might be a pretty nice guy.

You walked into the kitchen for some breakfast, which was spaghetti-pancakes. You were so used to eating this slop every morning that it tasted like nothing now. After eating, you got up from the table and put the plate in the sink. Sans appeared in front of you on your way into his room.

"What do you want?" You asked.

"follow me," He said.

You followed him, where he took a shortcut, and arrived at Grillby's. You've never been here before, but heard about it from Sans. He's told you about the asshole waiter there and that time he got in a fight with a group of dogs, but nothing else. You ordered your favorite drink since you've already eaten. Wait a second... if you've already eaten why did he take you to a food joint in the first place?

"hey kiddo..." Sans began. "you've been a good pet lately."

"And..?" You said, crossing your arms at the name 'pet.' 

"good pets get rewarded~" Sans said with a smirk.

"And how is that?" You asked.

"oh you'll see by tonight~" Sans whispered huskily in your ear.

You blushed as soon as you found out what he meant. Sans ordered some... mustard(?) for himself as you sipped your drink. You were astonished as he drank(ate?) the mustard. What the actual fuck? A group of dogs stopped by to talk to Sans for a bit.  They looked vicious nonetheless and you were scared of them. Humans are much weaker than these monsters after all.

"Hey uhhh Sansyyyyy," A dog slurred. She was probably drunk.

"heya," He said.

"Got anny money I can borrow?" She asked as she held out her hand.

"nope, i spent it all on mustard," He said as he shrugged.

"C'mon Sanssy I thought we was friends!" The dog slurred with an angry look.

"i'm out of money, i told ya!" Sans said.

"Come on, Cassie, he has no money!" A male dog said behind her as he grabbed her hand and pulled her. Cassie looked at Sans angrily before walking clumsily home.

You couldn't help but wonder, how did they not capture you if you're a human? You decided to ask Sans that question.

"Sans," You whispered. "Why didn't they capture me if I'm human?"

"none of the monsters underground know what a human looks like," Sans stated simply.

"Then how do you know I'm a human?" You asked.

That question seemed to catch him off guard, as he was sweating nervously before changing the subject.

"i'm done with my mustard let's go now," He said as he teleported you back to their house.

**Notes for the Chapter:**

> Sorry for another short chapter, I'll try to post at least another one today. If I can't, I'll post two tomorrow. Thanks for reading!


	10. A Taste of Dominance (NSFW)

**Summary for the Chapter:**

> The good pet turns bad. (im sorry not sorry)
> 
>  
> 
> Prepare for Sub!UF!Sans, cause that's hawt af...

**Notes for the Chapter:**

> Please don't kill me reader-chan

You ate dinner with Papyrus and Sans before heading off to the bathroom. You planned to give Sans a taste of his own medicine tonight, you were going to give him a taste of dominance. You did admit to yourself, you did like Sans, but it was very small and irrelevant. You were only domming tonight because you wanted to get back at Sans. You looked in the mirror, making sure you looked sexy enough for your plans, and headed into the bedroom.

Sans was waiting for you in there. He had no idea of your intentions, which made this all the more satisfying. He looked shocked at your appearance. You were wearing a new dark red bra that actually fit since your old one didn't fit anymore, and some lacy black panties. Sans felt himself tent in his shorts as he stared at you, not noticing the drool coming from his mouth.

"heh, come here my pet~" He said seductively. 

You walked slowly over to him as he tracked your every movement, eyes on your luscious thighs. You sat on the bed next to him, staring into his eyes for a second before averting his gaze. You sat on top of him and began to grind your hips onto his member. He was caught off guard as he moaned lightly, grinding into you. You bit your lip as your hands began to trail over his body, landing on his ribs.

You caressed his ribs, which must've been pretty sensitive since he let out a full moan to the touch. You kept on doing that, still rocking your hips forward as he moaned. He was close, you could tell due to his heavy breathing. He kept on going until he was about to release and stopped. 

"w-why'd you stop?" He said, still panting.

"This is your punishment for treating me bad," You said with a smirk. The roles have definitely changed now. 

Sans hesitated for a moment before gulping. "you wanna know the truth kid? fine. i only treat you bad because i don't wanna fall more in love with you!"

Now you were caught off guard. "W-What? Why is that a bad thing?"

"monsters aren't supposed to feel. they are ruthless and would kill each other for any stupid reason," Sans explained. "and if i loved someone and we got into a healthy relationship..."

There was a silence as he felt himself wilt.

"it'd all be reset," Sans said, hurt coating his voice.

"What do you mean?" You asked. You were so confused now.

"you mean you haven't died a single time?" Sans asked you.

"No, if I had I wouldn't be here right now," You said confusingly.

"look. you're a human with determination. with determination, you can reset the timeline. everybody forgets everything before the reset, well... i don't," Sans explained. 

"Wait, I have determination... so I can reset?" You took all of the information in, which was hard.

"yes.. wait a second... your determination overrides others," Sans said. He looked... hopeful. "that means as long as you don't die we're okay!"

Sans was smiling, genuinely, for once. You felt bad for him. If you had this knowledge and nobody else did, you'd have to redo everything to get back to this point. It was depressing, to say the least...

"Should we continue?" You asked seductively.

"sure, kiddo," Sans said, back to normal.

You rolled your hips against his member yet again, pressing your lips to his teeth to mimic a kiss. You asked for entrance and he obliged, parting his mouth as your tongue darted in. He explored your mouth as you moaned into the kiss, him bucking up at your core under his shorts. You felt a wet spot forming in your panties as you parted the kiss, breaking a strand of saliva connecting you two.

You pulled down his shorts, revealing his red member. You ignored it though, as you explored everywhere but there. You traced his ribs, his collarbone, his neck, he was panting again now. You put your hand near it, but missed the target when you trailed back up to his spine, feeling every ridge in it as he moaned. He melted in your hands so easy.

"Hmm? Wanting something?" You asked as Sans nodded. "Beg for it."

"t-touch me," Sans said.

"Hmm? Here?" You asked as you trailed your hands back onto his ribs.

"n-no lower..." He moaned.

"Here?" You said as you touched his pelvis. 

Sans caught you off guard as he grabbed your hand and put it on his member. He looked at you with lust-filled eyes as you stroked it, enjoying every sound he made from it. You kept on stroking before deciding to move on. You slowly lowered yourself onto his member with a moan.

You waited for a minute to adjust to the size, which you barely ever got to do. You've already done him like three times now and you still weren't used to it. When you were ready, you nodded to him as he started to thrust slowly. 

"_-___..." He moaned. He barely ever even said your real name.

He began to speed up, drawing out mewls from you every time he hit your spot. You rolled your hips in time with his thrusts as your panting sped up. You moaned as his thrusts became lightening fast as he came. You moaned as you came as well, him bringing you down from your orgasmic high with gentle thrusts before pulling out. He kissed you on the forehead before you fell asleep in his arms.


	11. Morning TV

**Summary for the Chapter:**

> Reader-Chan and Sans are starting to get into a proper relationship, hiding it from Papyrus. (basically...)

**Notes for the Chapter:**

> Yay! A chapter without NSFW! (finally) There might be some in the next chapter by the way...

You woke up beside Sans, who you think you're falling in love with by now. You didn't want to, he's a monster, you're a human, but you couldn't help it. What if Papyrus found out? Oh dear god, it'd be a lot of mayhem! If you were going to make this work, you'd have to be sneaky... But how sneaky can you be before being caught?

Sans woke up beside you, completely spent from last night. You two got up and went into the kitchen to eat some spaghetti-pancakes, but luckily, Papyrus wasn't there. It was odd, but he had to go to see Undyne, who you've heard would kill you in an instant. They kind of trained each other but were also good pals, but Papyrus would kill her in an instant if he could get a human soul for it. But why hasn't Papyrus killed you yet if he was that ruthless for your soul..? Was there a spec of good in him?

You pushed the thought aside as you decided to make some good breakfast for once. You grabbed the pancake mix and stirred it into a bowl before pouring it on the skillet. You waited for a minute before flipping the pancakes and serving them on a plate. You gave Sans two and you ate one, which he drowned his in mustard. (whyyyyyy!?) You sat down in front of Sans to eat. He took a bite before his eyes widened.

"oh my stars, kiddo" He said. "these pancakes are amazing!"

"Well you've never eaten any pancakes without spaghetti in them, so it's good to you. On the surface pancakes get a lot better than this..." You said. You didn't think you cooked very good, but it was decent cooking to you. "Do you think we'll ever get to the surface?"

"probably not..." Sans said dimly. "i'm harboring the human that's the key to our freedom and there probably won't be another one until a century..."

"A century!?" You said. 

"yea, a century, no shocker. it's not that long down here considering our life-span. i mean, i'm practically immortal since i'm already dead and you can reset so..." Sans said with a shrug, shoving more pancake into his mouth.

"Oh..." You said quietly before finishing your pancake.

"y'know kid..." Sans started, face flushed red as he chuckled a bit. "i think i might just be fallin for ya" 

"Sans, what does it mean when your face tints red? I asked before but never got an answer..." You said.

"fine..." Sans said, face even redder. "it means i'm blushing, alright?"

"Oh, how did I not notice that?" You said, laughing at yourself.

"it's alright, kiddo," Sans said, taking a last bite of his pancake before putting his plate away. 

"Can I take this collar off?" You asked.

"c'mon, i like it!" Sans pouted. "i can loosen it for you though..."

Sans loosened the collar around your neck. You could finally breathe properly for the first time in two weeks. Sans was actually sort of soft now, it was cute to say the least. You were finally putting the puzzle pieces together. From what you understood, Sans knows about timelines and resets, and you can reset, but he doesn't want you to. He is actually really nice but he hides it because monsters can't feel, well, other than him. You still didn't know much, but this is what you had a grasp on after a while of living there.

Sans lead you into the living room, which you two barely ever went in, and turned on the TV. The room wasn't so dim all of the sudden as colors filled your vision. It showed the same robot you seen live the other day on a cooking show. He must be very important here since you haven't heard of any other stars in the underground besides him. He was cooking a casserole, made of human soul substitute. You cringed at the idea of your soul being baked into a gross casserole as Sans scooted closer to you on the couch.

He was blushing as he held you against his chest, still watching the television. You blushed as well and tried to hide it in his jacket, but it done no good as he seen it anyways. He chuckled softly as he brushed some hair out of your face and leaned in to give you a peck on the lips.

You were starting to think of this place as home, since you've been here for a while. It's so familiar to you and the memories of the surface were so fuzzy now. You didn't mind staying down here anymore, even though you missed your family. Sans was your family now, all you needed was him. Despite all the things he did before, he was still adorable and you couldn't hate him for it. Every monster is like this, he was just trying to be like them. But now it's amazing, he's treating you like an actual person now and you want it to stay like this forever.

The cooking show ended with Mettaton pulling out a pre-cooked casserole after the last one failed, saying that on every cooking show they pre-cook every product as a laugh track occurred. Then the show ended with some credits, all of them saying Mettaton. That was a pretty bland show.

You jumped out of your position as an angry looking Papyrus slammed the door open. You sat farther away from Sans as he observed you two, Sans sweating nervously as well as you. You sank into the couch and crossed your arms as you tried to act casual.

"hey boss..." He said, trying to act casual as well.

"SANS! THEY WERE MAKING FUN OF MY PUZZLES!" Papyrus yelled, crossing his arms.

"but your puzzles are great," Sans said.

"I KNOW THAT LAZYBONES!" Papyrus yelled at him. "I'M GOING TO GO UPSTAIRS AND DRAW OUT BLUEPRINTS FOR SOME NEW ONES WHILE YOU MAKE YOURSELF USEFUL FOR ONCE INSTEAD OF LAYING AROUND!"

He stormed upstairs, stomping so hard it could break them. You were lucky he was so mad he didn't even acknowledge you, only Sans. Sans seemed upset before he teleported you two to his room. Well that was nerve-wrecking...


End file.
